The present invention relates to heating devices and more particularly to heating devices having burners which are of the type which mix gaseous fuel with air before igniting the mixture in a combustion chamber which may include a furnace or boiler.
Within industry and housing there has been a long felt need to develop efficient heating devices. Heating devices which burn gaseous fuels such as natural gas or liquified petroleum gas are common. However, to obtain the maximum benefit from the heating device, the device must utilize fuel burners which intermix the fuel and air to cause a generally complete burning of the fuel thus providing the greatest fuel efficiency and eliminating noxious by-products such as carbon monoxide which may be formed by incomplete combustion.
One of the principle drawbacks found in prior art heating devices for mixing fuel and air and igniting the mixture is that the devices attempt to mix generally parallel flows of air and fuel through use of swirling devices. While such devices perform adequate intermixing at the boundary between the air and fuels, the efficiency of the intermixing declines away from the boundary which causes incomplete combustion and noxious by-products. In addition, the gaseous fuels are typically lighter than air so that upon the release of the gas from the gas supply, the gas rises which may prevent optimal intermixing the gas and air.
Another drawback of these heating devices is the devices typically employ a plurality of rotating swirling mechanisms to swirl the fuel and/or combustion air. The swirling mechanisms may require tight tolerances and exact alignment to function properly. During fabrication or maintenance, the tolerances may not be met or the parts may be misaligned, both of which may have a negative effect on the intermixing on the fuel and air for complete combustion.
A further drawback of these heating devices is they typically produce flames having a long length extending away from the burner and a small cross sectional diameter. Heat exchangers are typically designed so that large surface areas are to be heated which increases the efficiency of the heat transfer. Therefore, the flame geometry of the heating devices is not optimal to transfer the heat to these heat exchangers and also creates hot spots on the surface of the heat exchanger which leads to localized stress fracturing and corrosion of the surface.
Therefore, it is an object of the present invention to provide a heating device which performs a complete intermixing of fuel such as natural gas or vaporized liquified petroleum and air so that there may be complete combustion of the oil.
Another object of the present invention is to provide a heating device which employs a minimum amount of swirling devices which may require exact alignment to intermix the fuel and air.
A further object of the present invention is to provide a heating device which provide a flame having a short length and a wide diameter so that a large surface area of a heat exchanger may be heated without producing localized hot spots.
A still further object of the present invention is to provide a heating device which restrains the gaseous fuel in a burner to facilitate the mixing of the fuel with air before ignition of the mixture.